Improved lathe-rest for truing watch-wheels



UNITED STATES PATENT OFFICE.

SAMUEL Gr. TVAMBLEY, OF BIDDEFORD, MAINE, ASSIGNOR TO CHARLES A. SHAW', OF SAME PLACE.

IMPOVED LATHE-REST FOR TRUING AWATCHWHEELS.

Specification forming part of Letters APatent No. 41,966, dated March l5, 1864.

To all whom, it may concern.-

Be it known that I, SAMUEL G. TWAMBLEY, of Biddeford, in the county of York and State of Maine, have invented a new and useful Improvement in Machines for Truing Watch- Wheels; and 1 hereby declare that theV following is a full, clear, and exact description of the same, reference being had to the aecompanying drawings, of which- Figure l is a side view of myimproved machine. Fig. 2 is a side View of my improved machine, showing the side opposite that shown in Fig. l. Fig. 3 is a transverse sectional View taken through the adjusting-screw. Fig. 4 is a view showing the method of constructing the faces of the head-piece and their springs when three faces are used.

Corresponding letters refer to corresponding parts.

In watch making and repairing wheels are frequently found all parts of the periphery or circumference of which are not equally distant from the center. Such wheels are said to be out of true,77 and while in that state the watch of which they form a part cannot be made to run correctly. The usual way of truing such wheels or bringing all parts equally distant from the center or axis is to fasten them into a lathe, and whilen they are revolving rapidly to turn them down by means of a file or stone heldin the hands of the workman and steadied by the rest of the lathe.

(The diiiiculties attending this method renders e it impossible to do good work4 by it, as is well known and understood by all practical watchlnakers; but these difficulties are entirely overcome by my improvement and the most desirable and perfect results attained, as will be understood by the following explanation:

In Fig. l, =A is a staff or upright having a double-faced head-piece, t' o, the faces standing at right angles to each other. On each of these faces is a flat steel spring, a c, attached by screws d z to the head-piece. Arranged in the top of the'head-piece is the adjustingscrew g, which, when it is turned in, comes into contact with the back of the spring a or c, as the case may be, as shown at b. To the outer face of the spring c, I cement a piece of a fine file, and to the spring a a piece of iine oil-stone, by means -of common lathe wax orl cement. v o

The operation of my invention is as follows: The wheel to be trued77 is put into a lathe, into the rest-slide of which the staff A is tted. The slide is then moved to such a position on the lathe as to bring the file on the spring c nearly into contact with the wheel. The screw g is then turned in so as to bring the file into contact with the wheel, which is then caused to revolve rapidly in the lathe, and is consequently turned @if or trued, the file being fed up to the wheel during the operation by the screw g as far as required, the spring to which it is attached allowing it to yield or give,7 so as not to injure the wheel, and still being sufficiently rigid to turn the wheel off perfectl y. After a wheel has been cut down sufficiently by the iile there is sometimes small fibers 0f brass or steel on the sides of the wheel which require to be stoned down.7 pur-pose the slidel of the lathe in which the stafi'A stands can be moved a little to one side and a little forward, so as to bring the stone on the spring a against the side of the wheel. In this way a wheel can be more rapidly and expeditiously trued than in any other manner. The same adjusting-screw, g, is used for both faces or springs.

I have used a stone and le together on the face or spring c, but prefer to have them on separate springs. I have also used three faces tothe head piece by placing one opposite the face o, and making the face o and the one opposite and their springs slotted, as shown in Fig. 4, so that when the screw g was used to adjust the spring on o it could ypass through the slot 7a in the opposite face m; and when used to adjust the spring on m it could pass through the slot k in o, the slot 7c being opposite the blank part of the face opposite-that is to say, the slot la in o being opposite the blank r in m, and the slot la in m being opposite the blank p in o when both faces were in For this.

position on the staff A; but this mode of construction adds to the cost, and the stone on the spring c, or the file on the spring c, can be brought to bear readily upon either side or the periphery of a wheel by a change of the slide or turning thestaff in the slide, and in claim- I stone mounted on a spring made adjustable by I Witnesses: i a screw, substantially in the manner und for many other Ways which Will readily suggest 2. In one piece of mechanism, the combina.. themselves to any workman. tionl of u le and stone, when mounted, sub- Haiving thus described my invention, I stuntially in the manner and for the purposes y hereinbefore described. l. In combination with the Staff A, a file or SAMUEL G. TWAMBLEY.

GHARLEs A. SHAW,

the purposes set forth and specified. l ALBERT PERKINS. 

